Does anyone saw, since the redising, all the music published, if you download it they are NOT copyrighted (like, they don't have the author's names or the album, in this case Newgrounds Audio Portal), and if this continues anyone can copy the song one of the musicans from newgrounds and then demand at the real author, because the downloaded file is like a normal file without copyright.

Those are ID3 tags. Those don't signify any copyright, they just provide info of the track like the album it's in, its title, its year, etc...

I don't see what the problem is in removing them. People were always still able to edit the ID3 tags themselves by right clicking on the file and clicking 'Properties'. Now they're just not there any more, but the Creative Commons license still stands.